Valve device

TECHNICAL FIELD

0001The present invention relates to a valve device, a fluid control device, a fluid control method, a semiconductor manufacturing apparatus, and a semiconductor manufacturing method.

BACKGROUND ART

0002For example, in the semiconductor manufacturing process, a fluid control device is used to control supply of various process gases to a chamber of a semiconductor manufacturing apparatus. For example, in an atomic layer deposition (ALD) method or the like, there is a need for a fluid control device small in size and capable of stably supplying process gases used in a process of depositing a film on a substrate at a more accurate flow rate.

0003Patent Literature 1 discloses a diaphragm valve used in such a fluid control device. The diaphragm valve comprises a seat removably disposed on a body and a seat holder that restrains the seat on the body. This sheet holder serves to support the periphery of the diaphragm in addition to restraining the seat on the body.

PATENT LITERATURE

0004PTL 1: Japanese Patent Application Laid-open No. 2015-036563

SUMMARY OF INVENTION

Technical Problem

0005In the diaphragm valve as disclosed in Patent Literature 1, there was a problem that the variation of flow rate between valves was relatively large.

0006The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a valve device which can stably supply a fluid with more accurate flow rate and suppress valve-to-valve variation in flow rate, a fluid control device, a fluid control method, a semiconductor manufacturing apparatus and a semiconductor manufacturing method using the valve device.

Solution to Problem

0007The valve device of the present invention comprises: a valve body made of metallic alloy defining a first flow path and a second flow path;

0008a valve seat disposed around an opening of the first flow path on the valve body;

0009an inner disk made of metallic alloy comprising: an inner annular portion that engages the valve seat to restrain the valve seat on the valve body; an outer annular portion disposed on the outer peripheral side of the inner annular portion and in contact with the valve body; and a connecting portion that connects the inner annular portion and the outer annular portion and has a plurality of openings communicating with the second flow path;

0010a diaphragm made of metallic-alloy, having a peripheral edge portion in contact with the outer annular portion, covering the inner disk and the valve seat and moving between an open position at which the diaphragm does not contact with the valve seat and a closed position at which the diaphragm contacts with the valve seat to enable and shut off communion between the first flow path and the second flow path; and

0011a presser adapter that presses a surface of the peripheral edge portion of the diaphragm opposite to the side of the outer annular portion, toward the outer annular portion to provide seals between the outer annular portion and the diaphragm and between the outer annular portion and the valve body,

0012wherein the inner disk has a hardness higher than the valve seat and lower than both the valve body and the diaphragm.

0013Preferably, among the valve body, the diaphragm and the inner disk, only the inner disk, or substantially only the inner disk is plastically deformed due to pressing by the presser adapter.

0014Preferably, the diaphragm has a lower hardness than the valve body,

0015and the inner disk has a lower hardness than the diaphragm.

0016More preferably, the inner disk has a hardness in a range of from Hv90 to Hv150, and the body has a hardness of Hv200 or higher, and the diaphragm has a hardness in a range of from Hv400 to Hv700.

0017Preferably, the outer annular portion of the inner disk has a first contact end face portion having an annular shape in contact with the diaphragm and a second contact end face portion having an annular shape in contact with the valve body, and the outer annular portion of the inner disk may be formed so that the area of the second contact end face portion is smaller than the area of the first contact end face portion before undergoing plastic deformation. In this case, the outer annular portion of the inner disk may be formed so that the radial width of the second contact end face portion is smaller than the radial width of the first contact end face portion before undergoing plastic deformation.

0018The fluid control device of the present invention is a fluid control device comprising a plurality of fluid devices arranged from an upstream side toward a downstream side, wherein the plurality of fluid device includes the above valve device.

0019The fluid control method of the present invention is a fluid control method comprising using the above-mentioned valve device for adjusting a flow rate of a fluid.

0020The semiconductor manufacturing apparatus of the present invention is a semiconductor manufacturing apparatus comprising the above valve device used for controlling a process gas in a manufacturing process of a semiconductor device requiring a process step using the process gas in a sealed chamber.

0021The semiconductor manufacturing method of the present invention is a semiconductor manufacturing method comprising using the above valve device for controlling a flow rate of a process gas in a manufacturing process of a semiconductor device requiring a process step using the process gas in a sealed chamber.

Advantageous Effects of Invention

0022According to the present invention, it is possible to more stably control the flow rate.

BRIEF DESCRIPTION OF DRAWINGS

0023<figref idref="DRAWINGS">FIG. 1</figref> is a partially cross-sectional view showing the configuration of a valve device according to an embodiment of the present invention.

0024<figref idref="DRAWINGS">FIG. 2</figref> is an enlarged cross-sectional view showing a closed state in the valve device of <figref idref="DRAWINGS">FIG. 1</figref>.

0025<figref idref="DRAWINGS">FIG. 3</figref> is an enlarged cross-sectional view showing an open state in the valve device of <figref idref="DRAWINGS">FIG. 1</figref>.

0026<figref idref="DRAWINGS">FIG. 4A</figref> is a front view of an inner disk.

0027<figref idref="DRAWINGS">FIG. 4B</figref> is a cross-sectional view of the inner disk taken along IVB-IVB line of <figref idref="DRAWINGS">FIG. 4A</figref>.

0028<figref idref="DRAWINGS">FIG. 5</figref> is an enlarged cross-sectional view of a portion in a circle A in <figref idref="DRAWINGS">FIG. 4B</figref>.

0029<figref idref="DRAWINGS">FIG. 6</figref> is an enlarged cross-sectional view showing an example of a plastic deformation of an outer annular portion.

0030<figref idref="DRAWINGS">FIG. 7</figref> is an enlarged cross-sectional view showing another example of a plastic deformation of the outer annular portion.

0031<figref idref="DRAWINGS">FIG. 8</figref> is a schematic diagram showing an application of the valve device according to an embodiment of the present invention to a semiconductor manufacturing process.

0032<figref idref="DRAWINGS">FIG. 9</figref> is a perspective view showing an exemplary fluid control device using the valve device of the present embodiment.

DESCRIPTION OF EMBODIMENTS

0033Embodiments of the present invention will be described below with reference to the drawings. In the description, the same elements are denoted by the same reference numerals, and repetitive descriptions are omitted as appropriate.

0034First, referring to <figref idref="DRAWINGS">FIG. 9</figref>, an exemplary fluid control device to which the present invention is applied will be described.

0035In the fluid control device shown in <figref idref="DRAWINGS">FIG. 9</figref>, a metallic base plate BS arranged along the width direction W<b>1</b>, W<b>2</b> and extending in the longitudinal directions G<b>1</b>, G<b>2</b> is provided. Note that W<b>1</b> represents the front side, W<b>2</b> represents the back side, G<b>1</b> represents the upstream side, and G<b>2</b> represents the downstream side. Various fluid devices <b>991</b>A to <b>991</b>E are installed on the base plate BS via a plurality of flow path blocks <b>992</b>, and a flow path (not shown) through which fluids flow from the upstream side G<b>1</b> to the downstream side G<b>2</b> is formed by the plurality of flow path blocks <b>992</b>.

0036The term “fluid device” as used herein refers to a device used in a fluid control device that controls the flow of fluids, the device comprises a body that defines a fluid flow path and has at least two flow path ports opening at the surface of the body. Specifically, the fluid device includes an open-close valve (two-way valve) <b>991</b>A, a regulator <b>991</b>B, a pressure gauge <b>991</b>C, an open-close valve (three-way valve) <b>991</b>D, a mass flow controller <b>991</b>E, and the like, but is not limited thereto. An introducing pipe <b>993</b> is connected to an upstream flow path port of flow path (not shown).

0037Although the present invention is applicable to various valve devices such as the above-described open-close valves <b>991</b>A and <b>991</b>D and the regulator <b>991</b>B, the present invention will be described by exemplifying an application of the present invention to an open-close valve (three-way valve) in the present embodiment.

0038<figref idref="DRAWINGS">FIG. 1</figref> is a cross-sectional view showing a configuration of a valve device <b>1</b> according to an embodiment of the present invention in a closed state. <figref idref="DRAWINGS">FIG. 2</figref> is an enlarged cross-sectional view showing the valve device of <figref idref="DRAWINGS">FIG. 1</figref> in a closed state. <figref idref="DRAWINGS">FIG. 3</figref> is an enlarged cross-sectional view showing the valve device <b>1</b> of <figref idref="DRAWINGS">FIG. 1</figref> in an open state.

0039As shown in <figref idref="DRAWINGS">FIG. 1</figref>, the valve device <b>1</b> includes a casing <b>6</b>, a bonnet <b>5</b>, a bonnet nut <b>8</b>, a valve body <b>2</b>, an inner disk <b>3</b>, a valve seat <b>48</b>, a diaphragm <b>41</b>, a presser adapter <b>43</b>, a diaphragm presser <b>42</b>, a stem <b>44</b>, and a coil spring <b>45</b>. It is assumed that arrows A<b>1</b> and A<b>2</b> in the drawing indicate the vertical direction, A<b>1</b> indicates the upward direction, and A<b>2</b> indicates the downward direction.

0040The valve body <b>2</b> is made of stainless steel and defines an upper surface <b>2</b><i>a</i>, a bottom surface <b>2</b><i>b </i>opposing thereto and side surfaces <b>2</b><i>c </i>and <b>2</b><i>d </i>facing each other. The valve body <b>2</b> defines a first flow path <b>21</b> and second flow paths <b>22</b>, <b>23</b>. The first flow path <b>21</b> and second flow paths <b>22</b> and <b>23</b> are respectively open at the bottom surface <b>2</b><i>b </i>of the valve body. The valve device <b>1</b> is a three-way valve that connects and shuts off the first flow path <b>21</b> and the second flow paths <b>22</b>, <b>23</b>, but the present invention is not limited to this, and the present invention can be applied to a two-way valve as a matter of course.

0041As shown in <figref idref="DRAWINGS">FIG. 2</figref> and <figref idref="DRAWINGS">FIG. 3</figref>, the valve body <b>2</b> defines a cylindrical portion <b>24</b> that extends in the upward direction A<b>1</b> from the upper surface <b>2</b><i>a</i>. A screw portion <b>25</b> into which the bonnet nut <b>8</b> is screwed is formed on the outer periphery of the cylindrical portion <b>24</b>. The inner circumferential side of the cylindrical portion <b>24</b> defines a valve chamber C<b>1</b> which houses the valve seat <b>48</b>, inner disk <b>3</b> and the diaphragm <b>41</b>. On the bottom surface <b>27</b> of the valve chamber C<b>1</b>, there is formed an annular groove <b>26</b> which communicates with one end of each of the flow paths <b>22</b>, <b>23</b>.

0042The casing <b>6</b> incorporates an actuator (not shown) that operates the diaphragm <b>41</b>, and this actuator is fixed to the bonnet <b>5</b> and a movable portion of the actuator is connected to a stem <b>44</b> extending in the vertical directions A<b>1</b> and A<b>2</b>. As the actuator, one driven by a driving gas such as compressed air is used, but the actuator is not limited thereto.

0043The outer peripheral surface <b>5</b><i>a </i>of the lower end portion of the bonnet <b>5</b> is fitted to the inner periphery of the cylindrical portion <b>24</b> of the valve body <b>2</b>, and the annular lower end face <b>5</b><i>b </i>of the bonnet <b>5</b> is in contact with the upper surface of the presser adapter <b>43</b>. By tightening the bonnet nut <b>8</b> screwed into the screw portion <b>25</b> of the cylindrical portion <b>24</b> of the valve body <b>2</b>, the bonnet nut <b>8</b> is engaged with the protruding portion <b>5</b><i>t </i>of the bonnet <b>5</b>, and the bonnet <b>5</b> is pressed downward A<b>2</b>. Between the annular lower end face <b>5</b><i>b </i>of the bonnet <b>5</b> and the bottom surface <b>27</b> of the valve chamber C<b>1</b> of the valve body <b>2</b>, the peripheral portion of the diaphragm <b>41</b> and the outer annular portion <b>31</b> of the inner disk <b>3</b> is interposed. In the present embodiment, the presser adapter <b>43</b> and the bonnet <b>5</b> are separated members, but the bonnet and the presser adapter may be integrally formed.

0044Inside the bonnet <b>5</b>, the stem <b>44</b> is biased by a coil spring <b>45</b> in the downward direction A<b>2</b> with respect to the bonnet <b>5</b>, that is, in the direction of moving the diaphragm <b>41</b> to the closed position.

0045The diaphragm presser <b>42</b> is fitted into the recess <b>44</b><i>a </i>formed in the lower end portion of the stem <b>44</b>. The diaphragm presser <b>42</b> is made of a synthetic resin such as polyimide which abuts the central portion of the upper surface of the diaphragm <b>41</b>. In the present embodiment, the coil spring <b>45</b> is used, but the present invention is not limited to this, and other types of elastic members such as a disc spring and a leaf spring can be used.

0046An annular protrusion <b>2</b><i>k </i>is formed around the opening of the flow path <b>21</b> on the bottom surface <b>27</b> of the valve chamber C<b>1</b> of the valve body <b>2</b>, and the valve seat <b>48</b> is fitted to the inner periphery of the annular protrusion <b>2</b><i>k </i>to be positioned on the bottom surface <b>27</b> of the valve chamber C<b>1</b>. The valve seat <b>48</b> is made of a resin such as PFA, PA, PI, PTFE, etc., but as described later, it may be a softer metal than inner disk <b>3</b>.

0047The inner disk <b>3</b> is disposed in the valve chamber C<b>1</b>, and has an inner annular portion <b>32</b>, an outer annular portion <b>31</b>, and a connecting portion <b>37</b> as shown in the <figref idref="DRAWINGS">FIGS. 4A, 4B</figref>. The inner disk <b>3</b> is made of a metallic material such as stainless steel alloy.

0048The inner annular portion <b>32</b> is disposed around the opening of the first flow path <b>21</b> and has an opening <b>33</b>. The outer annular portion <b>31</b> has an annular shape concentric with the inner annular portion <b>32</b>. The connecting portion <b>37</b> connects the inner annular portion <b>32</b> and the outer annular portion <b>31</b> and has a plurality of openings <b>34</b> communicating with the second flow path <b>22</b>.

0049The outer peripheral surface of the outer annular portion <b>31</b> is fitted to the inner peripheral surface of the cylindrical portion <b>24</b> of the valve body <b>2</b>. The first contact end face portion <b>31</b><i>f</i><b>1</b> having an annular shape on the upper side of the outer annular portion <b>31</b> contacts the lower surface of the peripheral edge portion of the diaphragm <b>41</b>. The second contact end face portion <b>31</b><i>f</i><b>2</b> having an annular shape on the lower side of the outer annular portion <b>31</b> contacts the flat bottom surface <b>27</b> of the valve chamber C<b>1</b> of the valve body <b>2</b>.

0050The shape of the inner peripheral surface of the opening <b>33</b> of the inner annular portion <b>32</b> and the shape of the outer peripheral surface of the valve seat <b>48</b> are formed to match with each other, and the inner peripheral surface of the opening <b>33</b> of the inner annular portion <b>32</b> is fitted from above onto the outer peripheral surface of the valve seat <b>48</b> positioned on the flat bottom surface <b>27</b> of the valve chamber C<b>1</b> of the valve body <b>2</b>, whereby the valve seat <b>48</b> is pressed against the bottom surface <b>27</b> by the inner annular portion <b>32</b> and is restrained on the bottom surface <b>27</b>.

0051The diaphragm <b>41</b> has a peripheral edge in contact with the first contact end face portion <b>31</b><i>f</i><b>1</b> of the outer annular portion <b>31</b> of the inner disk <b>3</b>, covers the inner disk <b>3</b> and the valve seat <b>48</b>, and defines a flow path connecting the flow path <b>21</b> with flow paths <b>22</b>, <b>23</b>. The diaphragm <b>41</b> connects and shuts off the first flow path <b>21</b> and the second flow path <b>22</b>, <b>23</b> by moving between a closed position at which the diaphragm contacts with the valve seat <b>48</b> and an open position at which the diaphragm does not contact with the valve seat <b>48</b>. The diaphragm <b>41</b> is made of, for example, a nickel alloy thin plate, cut out in a circular, and formed in an inverted dish shape in which the central portion is bulged upward. The diaphragm may be made of, for example, a stainless steel sheet or a laminate of a stainless steel sheet and a nickel-cobalt alloy sheet. Further, the diaphragm <b>41</b> may be a single diaphragm or a laminate obtained by laminating a plurality, and can be freely selected according to specifications and conditions.

0052The diaphragm presser <b>42</b> is always biased in the downward direction A<b>2</b> by the restoring force of the coil spring <b>45</b>, and as shown in <figref idref="DRAWINGS">FIG. 2</figref>, when the vicinity of the central portion of the diaphragm <b>41</b> is pressed by the diaphragm presser <b>42</b>, the diaphragm <b>41</b> is deformed and pressed to the valve seat <b>48</b>. As a result, the flow path between the first flow path <b>21</b> and the second flow paths <b>22</b>, <b>23</b> is closed.

0053When an actuator (not shown) is actuated to move the stem <b>44</b> in the upward direction A<b>1</b>, as shown in <figref idref="DRAWINGS">FIG. 3</figref>, the diaphragm <b>41</b> moves away from the valve seat <b>48</b>. As a result, the flow path between the flow path <b>21</b> and the flow paths <b>22</b>, <b>23</b> is opened, and the flow path <b>21</b> and the flow paths <b>22</b>, <b>23</b> communicate with each other.

0054In the valve device <b>1</b> of the above structure, in order to reliably provide seals between the peripheral portion of the diaphragm <b>41</b> and the outer annular portion <b>31</b> of inner disk <b>3</b> and between the outer annular portion <b>31</b> of inner disk <b>3</b> and the valve body <b>2</b>, the bonnet nut <b>8</b> is tightened to exert a force to push the presser adapter <b>43</b> downward A<b>2</b> by the lower end surface <b>5</b><i>b </i>of the bonnet <b>5</b>, and the presser adapter <b>43</b> presses the surface of the peripheral portion of the diaphragm <b>41</b> opposite to the side of the outer annular portion <b>31</b> toward the outer annular portion <b>31</b>.

0055Consequently, a plastic deformation that occurs between the diaphragm <b>41</b> and the inner disk <b>3</b> and between the valve body <b>2</b> and the inner disk <b>3</b> provide close seal between the members.

0056Structure of the Outer Annular Portion

0057<figref idref="DRAWINGS">FIG. 5</figref> shows an enlarged cross-sectional view of a circle A in <figref idref="DRAWINGS">FIG. 4B</figref>.

0058As shown in <figref idref="DRAWINGS">FIG. 5</figref>, the outer annular portion <b>31</b> of the inner disk <b>3</b> has a first contact end face portion <b>31</b><i>f</i><b>1</b> that is an annular flat surface in contact with the peripheral portion of the diaphragm <b>41</b> on the upper end side, and a second contact end face portion <b>31</b><i>f</i><b>2</b> that is an annular flat surface in contact with the bottom surface <b>27</b> of the valve chamber C<b>1</b> of the valve body <b>2</b> on the lower end side. The inner disk <b>3</b> contacts the diaphragm <b>41</b> only at the first contact end face portion <b>31</b><i>f</i><b>1</b>, and the diaphragm <b>41</b> is supported by the first contact end face portion <b>31</b><i>f</i><b>1</b>. The inner disk <b>3</b> is in contact with the bottom surface <b>27</b> of the valve chamber C<b>1</b> of the valve body <b>2</b> only at the second contact end face portion <b>31</b><i>f</i><b>2</b>. The inner annular portion <b>32</b> of the inner disk <b>3</b> is not in contact with the bottom surface <b>27</b> of the valve chamber C<b>1</b> of the valve body <b>2</b>.

0059An important point is that the width X<b>2</b> in the radial direction of the second contact end face portion <b>31</b><i>f</i><b>2</b> is formed to be smaller than the width X<b>1</b> in the radial direction of the first contact end face portion <b>31</b><i>f</i><b>1</b>. In the present embodiment, since the second contact end face portion <b>31</b><i>f</i><b>2</b> is located directly below the first contact end face portion <b>31</b><i>f</i><b>1</b> in the vertical directions A<b>1</b>, A<b>2</b>, the total area of the second contact end face portion <b>31</b><i>f</i><b>2</b> is smaller than the total area of the first contact end face portion <b>31</b><i>f</i><b>1</b>.

0060The second contact end face portion <b>31</b><i>f</i><b>2</b> may be positioned closer to the inner periphery or the outer periphery with respect to the first contact end face portion <b>31</b><i>f</i><b>1</b>, but the total area of the second contact end face portion <b>31</b><i>f</i><b>2</b> needs to be smaller than the total area of the first contact end face portion <b>31</b><i>f</i><b>1</b>.

0061The reason why the structure of <figref idref="DRAWINGS">FIG. 5</figref> is adopted for the outer annular portion <b>31</b> will be described later.

0062In order to suppress the variation in the flow rate between the plurality of valve device <b>1</b>, control of tightening torque of the bonnet nut <b>8</b> has conventionally been conducted.

0063However, in reality, only by controlling the tightening torque of bonnet nut <b>8</b>, it is not possible to sufficiently suppress the variation of the flow rate between the plurality of valve device <b>1</b>.

0064The present inventors have focused on the plastic deformation that occurs between the diaphragm <b>41</b> and the inner disk <b>3</b> and between the valve body <b>2</b> and the inner disk <b>3</b> as one of the reasons for the variation in the flow rate between the plurality of valve device <b>1</b>. That is, the relative positional relation between the diaphragm <b>41</b> and the valve seat <b>48</b> is considered to vary greatly depending on the amount of plastic deformation occurring between the diaphragm <b>41</b>, the inner disk <b>3</b> and the valve body <b>2</b> and the amount of deformation of the valve seat <b>48</b> made of resin. In a configuration in which plastic deformation occurs in each of the members, it is not easy to precisely control the relative positional relationship between the diaphragm <b>41</b> and the valve seat <b>48</b>.

0065Therefore, the present inventors have adjusted the relative hardness between the members that are the diaphragm <b>41</b>, the inner disc <b>3</b>, and the valve body <b>2</b>, and invented a configuration in which plastic deformation occurs only to the inner disk <b>3</b> or substantially only on the inner disc <b>3</b> by receiving a pressing force from the presser adapter <b>43</b>.

0066Specifically, assuming that the hardness of the valve seat <b>48</b> is H<b>1</b>, the hardness of inner disk <b>3</b> is H<b>2</b>, the hardness of the diaphragm <b>41</b> is H<b>3</b>, and the hardness of the valve body <b>2</b> is H<b>4</b>, the hardness H<b>1</b> to H<b>4</b> are adjusted so as to satisfy the following equation (1). <br />H1&lt;H2&lt;H3,H4  (1)

0067More specifically, the hardness H<b>1</b> of the valve seat <b>48</b> is adjusted to be within a range of from Hv(30) to Hv80 (converted from Rockwell because it cannot be measured by Vickers), the hardness H<b>2</b> of inner disk <b>3</b> is adjusted to be within a range of from Hv90 to Hv150, the hardness H<b>3</b> of the diaphragm <b>41</b> is adjusted to be within a range of from Hv400 to Hv700, and the hardness H<b>4</b> of the valve body <b>2</b> is adjusted to be within a range of from Hv200 to Hv400.

0068By employing a configuration in which plastic deformation occurs only in the inner disk <b>3</b> in the assembly of the valve device, it is possible to limit the factors that affect the relative positional relationship between the diaphragm <b>41</b> and the valve seat <b>48</b> to the plastic deformation of the inner disk <b>3</b>, and by precisely controlling the hardness of the inner disk <b>3</b>, it is possible to control the relative positional relationship between the diaphragm <b>41</b> and the valve seat <b>48</b>, thereby enabling suppression of variations in the flow rate between the plurality of valve devices <b>1</b>.

0069Next, an operation of the structure of the outer annular portion <b>31</b> shown in <figref idref="DRAWINGS">FIG. 5</figref> will be described.

0070<figref idref="DRAWINGS">FIG. 6</figref> and <figref idref="DRAWINGS">FIG. 7</figref> show an example in which the outer annular portion <b>31</b> of the inner disk <b>3</b> is subjected to a pressing force from the presser adapter <b>43</b>, and the second contact end face portion <b>31</b><i>f</i><b>2</b> is plastically deformed. Incidentally, in <figref idref="DRAWINGS">FIGS. 6 and 7</figref>, the plastic deformation in the first contact end face portion <b>31</b><i>f</i><b>1</b> is omitted.

0071When the outer annular portion <b>31</b> of the inner disk <b>3</b> receives a force F<b>1</b> from the presser adapter <b>43</b> through the periphery of the diaphragm <b>41</b>, the second contact end face portion <b>31</b><i>f</i><b>2</b> receives a reaction force F<b>2</b> from the bottom surface <b>27</b> of the valve body <b>2</b>. The force F<b>1</b> and the reaction force F<b>2</b> are directed in opposite directions and have the same magnitude.

0072The second contact end face portion <b>31</b><i>f</i><b>2</b> is plastically deformed by receiving a reaction force F<b>2</b>, and there may be a case where a part of the second contact end face portion <b>31</b><i>f</i><b>2</b> of the outer annular portion <b>31</b> is deformed so as to protrude to the inner peripheral side and the outer peripheral side as shown in <figref idref="DRAWINGS">FIG. 6</figref>, and a case where a part of the second contact end face portion <b>31</b><i>f</i><b>2</b> of the outer annular portion <b>31</b> is plastically deformed eccentrically to the inner peripheral side as shown in <figref idref="DRAWINGS">FIG. 7</figref>.

0073The important point is that forces of the same magnitude act in the opposite directions on the first contact end face portion <b>31</b><i>f</i><b>1</b> and the second contact end face portion <b>31</b><i>f</i><b>2</b>, but the total area of the second contact end face portion <b>31</b><i>f</i><b>2</b> is smaller than the total area of the first contact end face portion <b>31</b><i>f</i><b>1</b>. Therefore, the stress generated in the second contact end face portion <b>31</b><i>f</i><b>2</b> becomes larger than the stress generated in the first contact end face portion <b>31</b><i>f</i><b>1</b>, and the amount of plastic deformation of the second contact end face portion <b>31</b><i>f</i><b>2</b> is relatively larger as compared with the amount of plastic deformation of the first contact end face portion <b>31</b><i>f</i><b>1</b>. Along with the plastic deformation of the second contact end face portion <b>31</b><i>f</i><b>2</b>, the valve seat <b>48</b> is also pressed toward the bottom surface <b>27</b> of the valve body <b>2</b> by the inner annular portion <b>32</b>, and is deformed by an amount corresponding to the amount of plastic deformation of the second contact end face portion <b>31</b><i>f</i><b>2</b>. Even if the amount of plastic deformation of the second contact end face portion <b>31</b><i>f</i><b>2</b> is relatively increased, the position of the contact surface of the valve seat <b>48</b> with the diaphragm <b>41</b> in the vertical directions A<b>1</b> and A<b>2</b> and the position of the diaphragm <b>41</b> in the vertical directions A<b>1</b> and A<b>2</b> also move in the downward direction A<b>2</b>. As a result, the relative positional relationship between the diaphragm <b>41</b> and the valve seat <b>48</b> is maintained.

0074On the other hand, by relatively reducing the stress generated in the first contact end face portion <b>31</b><i>f</i><b>1</b>, the amount of plastic deformation of the first contact end face portion <b>31</b><i>f</i><b>1</b> becomes relatively small, and the variation in the relative positional relationship between the diaphragm <b>41</b> and the valve seat <b>48</b> becomes also relatively small.

0075When the amount of plastic deformation of the second contact end face portion <b>31</b><i>f</i><b>2</b> of the outer annular portion <b>31</b> is relatively increased, the adhesion between the bottom surface <b>27</b> of the valve body <b>2</b> and the second contact end face portion <b>31</b><i>f</i><b>2</b> is increased, and the sealability between the second contact end face portion <b>31</b><i>f</i><b>2</b> and the bottom surface <b>27</b> is improved.

0076Even if the amount of plastic deformation of the first contact end face portion <b>31</b><i>f</i><b>1</b> of the outer annular portion <b>31</b> is relatively reduced, since the pressing force of the presser adapter <b>43</b> acts on the inner disk <b>3</b> through the first contact end face portion <b>31</b><i>f</i><b>1</b>, the sealability between the diaphragm <b>41</b> and the first contact end face portion <b>31</b><i>f</i><b>1</b> is not significantly reduced.

0077According to the present embodiment, by adjusting the relative hardness between the members, the member subjected to plastic deformation in the assembly of the valve device <b>1</b> is limited to the inner disk <b>3</b> alone, and by accurately controlling the hardness of the inner disk <b>3</b>, it is possible to easily and more accurately control the relative positional relationship between the diaphragm <b>41</b> and the valve seat <b>48</b>. Consequently, it is possible to suppress the variation in the flow rate that occurs between the plurality of valve devices <b>1</b>.

0078Further, according to the present embodiment, by adjusting the relative areas of the first contact end face portion <b>31</b><i>f</i><b>1</b> and the second contact end face portion <b>31</b><i>f</i><b>2</b> of the outer annular portion <b>31</b> of the inner disk <b>3</b>, it is possible to adjust the stresses generated in the first contact end face portion <b>31</b><i>f</i><b>1</b> and the second contact end face portion <b>31</b><i>f</i><b>2</b>, and it is possible to relatively increase the amount of plastic deformation of the second contact end face portion <b>31</b><i>f</i><b>2</b>. As a result, it is possible to improve the sealing between the second contact end face portion <b>31</b><i>f</i><b>2</b> and the valve body <b>2</b> while suppressing the variation in the relative positional relationship between the diaphragm <b>41</b> and the valve seat <b>48</b>.

0079Next, referring to <figref idref="DRAWINGS">FIG. 8</figref>, an application of the above-described valve device <b>1</b> will be described.

0080Semiconductor manufacturing apparatus <b>980</b> shown in <figref idref="DRAWINGS">FIG. 8</figref> is an apparatus for performing a semiconductor manufacturing process by ALD method, where <b>981</b> is a process gas supply source, <b>982</b> is a gas box, <b>983</b> is a tank, <b>984</b> is a control unit, <b>985</b> is a processing chamber, and <b>986</b> is an exhaust pump.

0081In the semiconductor manufacturing process by the ALD method, it is necessary to precisely adjust the flow rate of the process gas, and along with the increase of the diameter of the substrate, it is also necessary to ensure a certain amount of flow rate of the process gas.

0082The gas box <b>982</b> is an integrated gas system (fluid control device) housed in the box by integrating various fluid control devices such as open-close valves, regulators, mass flow controllers, etc. in order to supply accurately metered process gas to the processing chamber <b>985</b>.

0083The tank <b>983</b> functions as a buffer for temporarily storing the process gas supplied from the gas box <b>982</b>.

0084The control unit <b>984</b> executes flow rate adjusting control by supply control of the operating gases to valve device <b>1</b>.

0085The processing chamber <b>985</b> provides a sealed processing space for forming a film on a substrate by the ALD method.

0086The exhaust pump <b>986</b> draws a vacuum within the processing chamber <b>985</b>.

0087According to the above-described system configuration, since a process gas with an accurate flow rate can be stably supplied to the processing chamber, the wafer can be uniformly deposited.

0088Note that the present invention is not limited to the above-described embodiment. Various additions, modifications and the like can be made by those skilled in the art within the scope of the present invention. For example, in the above application example, the case where valve device <b>1</b> is used in the semiconductor manufacturing process by the ALD method has been exemplified, but the present invention is not limited to this case, and the present invention can be applied to any object that requires precise flow rate control, such as an atomic layer etching (ALE method), for example.

0089In the above embodiment, as an actuator, a piston incorporated in the cylinder operated by gas pressure is used, but the present invention is not limited to this, and it is possible to select various optimal actuator according to the control object.

0090In the above embodiment, the valve device <b>1</b> is configured to place the outside of the gas box <b>982</b> as a fluid control device, but it is also possible to include the valve device <b>1</b> of the above embodiment in a fluid control device in which various fluid devices such as open-close valves, a regulator, a mass flow controller are integrated and housed in a box.

0091In the above embodiment, the valve device is mounted on a plurality of flow path blocks <b>992</b> in a fluid control device, but the valve device of the present invention can be applied to an integrated flow path block or a baseplate in addition to the divided flow path block <b>992</b>.

REFERENCE SIGNS LIST

0000<ul id="ul0001" list-style="none"><li id="ul0001-0001" num="0092"><b>1</b>: Valve device</li><li id="ul0001-0002" num="0093"><b>2</b>: Valve body</li><li id="ul0001-0003" num="0094"><b>2</b><i>a</i>: Upper surface</li><li id="ul0001-0004" num="0095"><b>2</b><i>b</i>: Bottom surface</li><li id="ul0001-0005" num="0096"><b>2</b><i>c</i>,<b>2</b><i>d</i>: Side surface</li><li id="ul0001-0006" num="0097"><b>2</b><i>k</i>: Protrusion</li><li id="ul0001-0007" num="0098"><b>3</b>: Inner disk</li><li id="ul0001-0008" num="0099"><b>5</b>: Bonnet</li><li id="ul0001-0009" num="0100"><b>5</b><i>a</i>: Outer surface</li><li id="ul0001-0010" num="0101"><b>5</b><i>b</i>: Lower end face</li><li id="ul0001-0011" num="0102"><b>5</b><i>t</i>: Protruding portion</li><li id="ul0001-0012" num="0103"><b>6</b>: Casing</li><li id="ul0001-0013" num="0104"><b>8</b>: Bonnet nut</li><li id="ul0001-0014" num="0105"><b>21</b>: First flow path</li><li id="ul0001-0015" num="0106"><b>22</b>,<b>23</b>: Second flow path</li><li id="ul0001-0016" num="0107"><b>24</b>: Cylindrical portion</li><li id="ul0001-0017" num="0108"><b>25</b>: Screw portion</li><li id="ul0001-0018" num="0109"><b>26</b>: Annular groove</li><li id="ul0001-0019" num="0110"><b>27</b>: Bottom surface</li><li id="ul0001-0020" num="0111"><b>31</b>: Outer annular portion</li><li id="ul0001-0021" num="0112"><b>31</b><i>f</i><b>1</b>: First contact end face portion</li><li id="ul0001-0022" num="0113"><b>31</b><i>f</i><b>2</b>: Second contact end face portion</li><li id="ul0001-0023" num="0114"><b>32</b>: Inner annular portion</li><li id="ul0001-0024" num="0115"><b>33</b>: Opening</li><li id="ul0001-0025" num="0116"><b>34</b>: Opening</li><li id="ul0001-0026" num="0117"><b>37</b>: Connecting portion</li><li id="ul0001-0027" num="0118"><b>41</b>: Diaphragm</li><li id="ul0001-0028" num="0119"><b>42</b>: Diaphragm presser</li><li id="ul0001-0029" num="0120"><b>43</b>: Presser adapter</li><li id="ul0001-0030" num="0121"><b>44</b>: Stem</li><li id="ul0001-0031" num="0122"><b>44</b><i>a</i>: Recess</li><li id="ul0001-0032" num="0123"><b>45</b>: Coil spring</li><li id="ul0001-0033" num="0124"><b>48</b>: Valve seat</li><li id="ul0001-0034" num="0125"><b>980</b>: Semiconductor manufacturing apparatus</li><li id="ul0001-0035" num="0126"><b>981</b>: Process gas supply source</li><li id="ul0001-0036" num="0127"><b>982</b>: Gas box</li><li id="ul0001-0037" num="0128"><b>983</b>: Tank</li><li id="ul0001-0038" num="0129"><b>984</b>: Control unit</li><li id="ul0001-0039" num="0130"><b>985</b>: Processing chamber</li><li id="ul0001-0040" num="0131"><b>986</b>: Exhaust pump</li><li id="ul0001-0041" num="0132"><b>991</b>A: Open-close valve (fluid device)</li><li id="ul0001-0042" num="0133"><b>991</b>B: Regulator (fluid device)</li><li id="ul0001-0043" num="0134"><b>991</b>C: Pressure gauge (fluid device)</li><li id="ul0001-0044" num="0135"><b>991</b>D: Open-close valve (fluid device)</li><li id="ul0001-0045" num="0136"><b>991</b>E: Mass flow controller (fluid device)</li><li id="ul0001-0046" num="0137"><b>992</b>: flow path block</li><li id="ul0001-0047" num="0138"><b>993</b>: Introducing pipe</li><li id="ul0001-0048" num="0139">A<b>1</b>: Upward direction</li><li id="ul0001-0049" num="0140">A<b>2</b>: Downward direction</li><li id="ul0001-0050" num="0141">BS: Base plate</li><li id="ul0001-0051" num="0142">C<b>1</b>: Valve chamber</li><li id="ul0001-0052" num="0143">G<b>1</b>: longitudinal direction upstream side</li><li id="ul0001-0053" num="0144">G<b>2</b>: Longitudinal direction downstream side</li><li id="ul0001-0054" num="0145">H<b>1</b>-H<b>4</b>: Hardness</li><li id="ul0001-0055" num="0146">W<b>1</b>: Width direction front side</li><li id="ul0001-0056" num="0147">W<b>2</b>: Width direction back side</li><li id="ul0001-0057" num="0148">X<b>1</b>: First contact end face width</li><li id="ul0001-0058" num="0149">X<b>2</b>: Second contact end face width</li></ul>